Pneumatic hammer



Jan. 4, 1938. .1. w. osBoRN PNEUMATIC HAMMER Filed Aug. 5. 195e INVENTOR.

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Patented Jan. 4, 193s UNITED N STATES awaits rNEUMA'rro nAMMEn John W. Osborn, Jackson. Mich., assigner to Hinckley-Myers Company, Jackson, Mich., a corporation Vof Michigan Application August: s, 193s, swarm. l 94,377

'1 claims. (cl. 121-35) My invention relates to an improved pneumatic hammer or fluid pressure operated vibratory impact device of a similar character.

An object is to providea simple, compact device of the character described which is of a strong and durable construction, easily operable and inexpensive to build and which comprises a minimum number of rugged readily assembled rugged parts.

A meritorious feature resides in improved iluid pressure actuated mechanism `of the vibratory` type and particularly to an improved type of piston structure adapted in its reciprocation to control the admission of fluid to operate the piston and the associated parts. l

A `further meritorious feature resides in the provision of an improved iluid pressure control valve by `which the ow of iluid under` pressure `to the fluid actuated part within the cylinder is regulated and controlled and a tight seal is maintained at such valve against leakage o1' fluid at such point.

A further meritorious feature is the provision in a structure of the character described of improved manually operable control valve mechanism to regulate the admission of iluid to the cylinder in conjunction with ameterlng or measuring valve which determines the amount of iluid admitted into the cylinder by the control valve. l

Other objects, advantages, and meritorious features of my invention will more fully appear from the following description, appended claims, and accompanying drawing, wherein:

Figure 1 is a side elevation of a pneumatic hammer structure embodying my invention and being partly broken away to` show` the interior thereof,

Fig. 2 is a horizontal sectional view taken on line`2-2 of Fig. 1, and

Fig. 3 is a plan of the upper end of the plunger. My improved pneumatic'tool `has a T-shaped casing which includes a handle portion I0 `and a head portion I2. 'I'he head is `cored out to provide a cylinder within which piston element I4 is mounted to reciprocate. One end `of the cored out casing or cylinder is closed with a screw cap I6.

The opposite end of the head `is exteriorly threaded to receive'a cooperatively` internally threaded retainer ring lil.` Plunger20 is slidably` supported within the retainer ring upon a spring 22 which in turn is supported upon a'stepped split washer 23. Thisplunger 20 has a ange 2| which rests upon the spring. `"I'heend oi the plunger is recessed as shown to receive the re duced end of the piston I4.` Flange 2| is cut away at 21 as shown in Fig..3 to permitthreaded A insertion oi the spring through the-cut out into place upon the plunger.

The cored out interior of the casing head forms 5 the cylinder 24` Within which the piston .I4 is slidably disposed. This cylinder 24 is provided with a wall recess in the form of a circumferential channel or groove 28 of greater diameter than the diameter ofthe cylinder. Theupper 10 end? of the piston constitutes a portionoi' maximum diameter and forms a tight slidable flt within the cylinder. Such upper end is hollowed out as at 32 and a plurality of il'uid' communicatingports 34 lead from such hollowed out in- 15 terior to a channel or groove 36 extending about such maximum diameter portion of thepiston as shown in Fig. 1. The opposite end 30 of the piston is of less diameter. The juncture ci such lower end portion 30 of the piston with the maxi- 2 mum diameter portion thereof forms a shoulder 31 which,` with the channelY or groove 36, makes up a ledge` or skirt 38. The reduced endfpor` tion 30 of the piston is slidable within an ex- .tension 2G of the cylinder 24.

A handle I0 is provided with a fluid inlet 40 25 which leads into a cored out passageway 42. The flow of fluid through this passageway 42 is controlled by a `valve assembly including va1ve`46 held snugly seated by a spring 48,` which spring 30 may be overcome by a manually operable lever 44 to lift the valve 46 to permit air to ow through the cored out passageways in valveplug 50, which carries the valve 46. Plug 50 is provided on opposite sides with grooves or channels 35 5l: A plurality of angularpassageways 52, three being here shown, lead kfrom each of these channels 5| through the valve plug 50 so as to establishcommunication between the valve chamber above said plug and the uid passageway 42 40 through the handle of the casing.

The passageway V42 that leads axially through the handle Ill communicates adjacent to the head of the casing with the fluid inletl43 into thecylirider. This iluid inlet is spaced below 45 the passageway 42 through thehandle and communication therebetween is controlled by a rotatable valve 53 having a knurled end 54 `whereby ltmay be rotated to bring the val've passageway 56 into position to permit a controlled 5p amount of air to flow therethrough as shown in Figs. 1 and 2"or to shut oft' such ow asis obvious `from the construction illustrated. It is apparent that the valve 53 may be manipulated to varying positions to regulate the size of the 55 communicating passageway between the air inlet 42 through the handle and the airinlet 43 into the cylinder.

The operation is apparent from the above description. Air enters through intake 40 into passageway 42 through the handle.. With the valve 46 positioned as shown in Fig. l the flow of air is blocked at this point. Upon depression of'the lever 44 compressing spring 48 the control valve 4G is lifted from the top of the plug 50 into the valve chamber above said plug. This uncovers the angular' air passageways 52 through the plug which establishes communication between the two portions of the air passageway 42 through the handle on opposite sides of the plug 50.

Air iiows through the angular passageways 52 on the pressure side of the plug upwardly and over the valve face of Jthe plug and downwardly through the angular passageways 52 on the opposite sides of the plug into that end of the passageway 42 of the handle adjacent to the head of the casing. From here, with the valve 53 positioned as illustrated fully opened) air ows through the passageway 55 through such valve into inlet 43 which leads into the cylinder 24 in the head.

Air pressure within the cylinder acts upon the lower shoulder 3'! of the sldrt 38 of the pistonraising` the piston toward the upper end of the cylinder. When the piston is elevated suiilciently to bring shoulder 38 into the circumferential wall recess 28 of the cylinder or to place the reduced end 3Q of the piston in registration with such wall recess 28 of the cylinder the plurality of air pressure escape passageways 3,4 through the piston will open through the groove 35 to the recess 28 within the cylinder. In this position air under pressure flows from the lower end of the cylinder through the wall recess 28 through piston groove 36 and ports 34 into the cored out upper end 32 of the piston to the upper end of the cylinder. Air continues to flow into the upper end of the cylinder above the piston until the pressure is raised suiriciently to drive the piston downwardly so that the lower end of the reduced diameter portion 30 strikes against the upper end of the plunger 3D urging the same downwardly against the tension of the spring 22.

Downward movement of the piston uncovers the apertures 25 in the cylinder and the air escapes frorn the cylinder 24 above the piston to the atmosphere. This downward movement of the piston also moves air escape openings 34 in the piston below the wall recess 28 in the cylinder wall to the position shown in Fig. 1 so as to prevent any flow of air from the air inlet end of the piston to the upper end of the piston. It will be noted that when the groove 3E in the piston is in registration with wall recess 28 in the cylinder that the air out-let openings 25 of the cylinder are closed by the piston.

What I claim:

1. In a fluid pressure device of the character described. a. casing having a handle and a head portion, said head portion hollowed out to form a fluid Acylinder having a uid outlet, said uid cylinder having a iluid inlet extending through said handle, a piston within the cylinder, avalve casing plug extending transversely across the uid inlet through the handle, said plug having a valve chamber at one end and having a valve stem passageway therethrough, a valve having a head adapted to seat against the end of the plug within the valve chamber and having a stem extending through said valve stem passageway, a spring holding said valve to its seat against the end of the plug. mechanism for unseating said valve against the tension of said spring, said plug having two uid passageways leading from the valve chamber to the fluid passagewaythrough the handle on opposite sides of the plug and adapted to be normally closed by the valve seated against the end of the plug within the chamber.

2. In a iluid pressure device of the character described, a. casing having a handle and a head portion, said head port-ion hollowed out to form a fluid cylinder having a uid outlet, said fluid cylinder having a iiuid inlet extending through said handle, a pist-on Within the cylinder, a valve carrying plug and a valve normally closing said uid passageway through the handle, said valve adapted to seat against the end face of the plug within a valve chamber at such end of the plug,

said plug provided with two fluid passageways which lead from the valve face thereof to the fluid passageway through the handle but on opposite sides of the plug, means normally holding the valve seated against the valve seat of the plug to close said passageway, means operable to lift the valve from said valve face to establish communication through said passageways with the fluid passageway through the handle on opposite sides of the plug.

3. Ina :luid pressure device of the character described. casing having a handle anda head portion, said head portion'hollowed out to form a fluid cylinder having a iluid outlet, said cylinder having a duid inlet extending through said handle, a piston within the cylinder, a valve adapted to 'control the fluid passageway through the handie, means for operating said valve to open said passageway, and a second Valve regulating the flow through said passageway from the iirst valve tothe cylinder, said second valve adjustable to vary the extent of valve opening and adapted to maintain any position to which it may be adjusted.

'4. In a fluid pressure device of the character described a casing having a handle portion provided with a fluid passageway extending therethrough, said casing having a head portion hollowed out forming'a fluid cylinder provided adjacent to one end with a fluid outlet, such cylinder also provided with a. fluid inlet communicating with the fluid'passageway through the handle, a piston slidable within the cylinder, manually operable valve mechanism controlling the fluid passageway through the handle, spring means normally holding said valve to close said passageway, and a second valve manually adjustable to vary the flow of fluid through said passageway.

5. In a iluid pressure device of the character described a casing having a handle portion provided with a iiuid passageway extending therethrough, said casing having a head portion hollowed out forming a fluid cylinder provided adjacent to one end with a iluid outlet, such cylinder also provided with a. fluid inlet communicating with the fluid passageway through the handle, a piston slidable within the cylinder, a valve casing plug extending transversely across the uid passageway through the handle and having one end adapted to serve as a valve seat, a valve chamber adjacent to said end of the plug communicating with the iiui'd passageway through the handle, a valve having its head disposed within the valve chamber and adapted to seat against the adjacent end of the plug and having its stem slidable through said plug, said plug provided with a valve passageway controlled by said valve and also provided with a fluid inlet communicating with the uid passageway through the handle, a piston slidable within the cylinder, a valve casing plug extending transversely across the iiuid passageway through the handle and having one' end adapted to serve as a valve seat, a valve chamber adjacent to said end of the plug having communication with the uid passageway through the handle on opposite sides of the plug, a valve having its head disposed within said chamber and having a stem slidable through said plug, said valve controlling the fluid communication through the handle passageway between opposite sides of the plug, said valve being manually operable and provided with a spring adapted to maintain the valve normally closed.

7. In a iluid pressure device of the character described a casing having a handle portion provided with a. fluid passageway extending therethrough, said casing having a head portion hollowed out forming a fluid cylinder provided adjacent to one end with a fluid outlet, such cylinder also provided with a fluid inlet communicating with the uid passageway through the handle,a piston slidable within the cylinder, a valve casing plug extending transversely across the uid passageway through the handle and having one end adapted to serve as a valve seat, a valve chamber adjacent to said end of the plug having communication with the iluid passageway through the handle on opposite sides of the plug, a valve having its head disposed within said chamber and having a stem slidable through saidplug, said valve adapted when seated against the end of the plug to prevent ow of iluid through the handle passageway into the cylinder and adapted when spaced from the end of the plug to permit such ilow of fluid, a yspring normally holding said `valve seated against the end of the plug and manual means for actuating said valve against the resistance of said spring.

JOHN W. OSBORN. ll 

